I would guess B as well. Counting the number of angles/sides, you get 12, 7, 9, 6, __. One possible pattern I see would continue 6, 5, 3, 4, 0, 3, which would make B the right answer. Of course, another possible pattern I see would continue 8, 7, 9, making A the right answer; but since this pattern kind of breaks down after that and the polygons are alternating (at least so far) between one and two per picture, I'm disinclined to go with A. Of course, it's entirely possible that the correct answer is based on a pattern I'm not seeing at all.

If you take away all the edges in the diagram, and see just the points, then you can draw a single convex polygon with all those points as vertices. The pattern is the number of those vertices: 8, 6, 6, 4, 4.

Polygon number three looks like a merge of the first two pictures, with maybe some rotation involved. If so then logically, the fifth polygon will be a merge of pictures 3 and 4. Therefore B is the answer. Or not.